1. Field
This invention relates to the field of location services for use in mobile devices or mobile stations, and more particularly to use of location services equipment identity information in providing location services in a wireless communication system.
2. Description of Related Art
Location services (abbreviated as LCS, for “LoCation Services”) for mobile telephones and wireless digital communication devices (collectively referred to hereinafter as Mobile Stations) are an increasingly important business area for wireless communication providers. Location information can be used to provide a variety of location services to mobile station users. For example, public safety authorities can use location information to pinpoint the location of a wireless device. Alternatively, a mobile station user can use location information to find the location of the nearest automatic teller machine, as well as the fee charged by the ATM. As another example, location information can assist a traveler in obtaining step-by-step directions to a desired destination while en route.
Technologies that permit a large number of system users to share a communication system, such as Code Division Multiple Access (CDMA) and Wideband CDMA (WCDMA) technology, play an important role in meeting the ever-increasing demands of mobile computing, including the demands for location services. As is well known, CDMA and WCDMA communication devices are assigned a unique code and each mobile device uses its code to spread its communication signals across a common spread-spectrum bandwidth. As long as each communication device uses its correct code, it can successfully detect and select a desired signal from among other signals concurrently transmitted over the same bandwidth.
Other multiple mobile station signal access techniques include time division multiple access (TDMA) and frequency division multiple access (FDMA). There are also analog frequency modulation (FM) based wireless communication systems, such as the well known Advanced Mobile Phone System (AMPS). In addition, many wireless communication devices combine communications capabilities with global position system (GPS) techniques. Some wireless communication systems are capable of operating using multiple techniques, such as CDMA and GPS, or on different frequency bands, such as cellular or Personal Communication Services (PCS) bands. For example, the Global System for Mobile Communications (GSM) uses a combination of TDMA and FDMA technology. GSM systems also frequently employ General Packet Radio Service (GPRS) technology to transmit data and to provide location services.
Standards and functional specifications for LCS in wireless communication systems have been established. One exemplary reference relating to GSM and LCS is the 3rd Generation Partnership Project (3GPP), Technical Specification Group (TSG) Services and System Aspects, Technical Specification Group GSM/EDGE Radio Access Network, Functional stage 2 description of Location Services (LCS) in GERAN, (3GPP TS 43.059). Another exemplary reference is 3rd Generation Partnership Project, Technical Specification Group Radio Access Network, Stage 2 functional specification of User Equipment (UE) positioning in UTRAN, (3GPP TS 25.305). These technical specification documents are hereby fully incorporated by reference herein as though set forth in full, for teachings relating to mobile station location services. The incorporated references are referred to hereinafter as 3GPP TS 43.059 and 3GPP TS 25.305, respectively.
In typical use, and as set forth in greater detail in the incorporated 3GPP TS 43.059 reference, a mobile station (MS), which may comprise a mobile phone, a laptop, palmtop, or other conventional mobile device, or combination thereof, establishes a communication link with a base station system (BSS). A BSS typically includes a plurality of base station transceiver systems (BTSs) and a base station controller (BSC). A location server, such as a Serving Mobile Location Center (SMLC) (in a GSM system), provides location services to the MS as needed, such as coordinating the exchange of information from which the location of the MS can be determined. The location server may be part of a BSS, or it may be a separate server coupled to either a sole BSS or a system of BSSs.
Any given MS may comply with various international equipment standards, and may have accurate standard performance data available. In addition, any given communication system, such as one conforming to a current GSM specification, may not have adopted known equipment standards. In addition, any given MS may also have known manufacturing defects. An MS may be assigned an identification code, such as, for example, an “International Mobile Equipment Identifier” (IMEI) used in GSM systems and WCDMA systems, or an “Electronic Serial Number” (ESN), used in IS-95 and CDMA2000 systems.
A communication system may also maintain a database on an equipment identification server (EIS), such as an equipment identity register (EIR) in a GSM system, correlating users with particular equipment. An EIS may be incorporated into other parts of a communication system, such as a mobile switching center (MSC) or a gateway switching server (GSS). Such a database may have a unique code assigned to the user or to the equipment. The particular equipment properties and method location services operation of an MS can have a significant impact on the ability of a location server to efficiently and accurately provide LCS capabilities.
Another aspect of LCS relates to the use of an MS in geographical areas in which communication service provider networks employ different manufacturer models of location server equipment. Different location servers models interact with the MS according to the particular design characteristics of both the MS equipment and the location server equipment. For a given combination of MS equipment and location server equipment, there is a preferred set of messages and communication protocols that will enable determination of the MS location with optimal efficiency. By reading the Location Area Identifier (LAI), which is transmitted on the common channels, the MS can determine, using database information, which model of position location server is used in that particular network. Similarly, the MS can also determine the Operator Identification (ID) based upon broadcast information. The Operator ID can be related through database information to the position location server equipment.
In light of the foregoing, persons skilled in the wireless communications art shall recognize that significant improvements in providing LCS can be achieved by improving the messages exchanged between the MS and the location server. This can be advantageously accomplished by an inventive system, method and apparatus wherein the location server and the MS, either or both, obtain and use the LCS equipment identification information when providing LCS services.